HYPERCAPNBIC NORMALIZATION OF BOLD FMRI: COMPARISON ACROSS FIELD STRENGTHS & PU

BOLD FMRI 的高碳酸正常化：跨场强的比较

• 批准号: 7601623
• 负责人: SEONG KIM
• 金额: $ 4.72万
• 依托单位: UNIVERSITY OF MINNESOTA
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-06-01 至 2008-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7601623
• 关键词: Behavior; Blood; Blood Volume; Blood capillaries; Breathing; Cerebrovascular Circulation; Cerebrum; Computer Retrieval of Information on Scientific Projects Database; Condition; Data; Effectiveness; Fingers; Functional Magnetic Resonance Imaging; Funding; Gases; Grant; Hypercapnia; Institution; Localized; Methods; Motor; Movement; Physiologic pulse; Physiological; Pulse taking; Research; Research Personnel; Resources; Rest; Signal Transduction; Source; Specificity; Stimulus; Tissues; United States National Institutes of Health; Veins; Venous; base; blood flow measurement; blood oxygen level dependent; capillary; human subject; improved; magnetic field; neural stimulation; relating to nervous system; response; size

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The blood oxygenation level-dependent (BOLD) functional magnetic resonance imaging (fMRI) signal response to neural stimulation is influenced by many factors that are unrelated to the stimulus. These factors are physiological, such as the resting venous cerebral blood volume (CBV(v)) and vessel size, as well as experimental, such as pulse sequence and static magnetic field strength (B(0)). Thus, it is difficult to compare task-induced fMRI signals across subjects, field strengths, and pulse sequences. This problem can be overcome by normalizing the neural activity-induced BOLD fMRI response by a global hypercapnia-induced BOLD signal. To demonstrate the effectiveness of the BOLD normalization approach, gradient-echo BOLD fMRI at 1.5, 4, and 7 T and spin-echo BOLD fMRI at 4 T were performed in human subjects. For neural stimulation, subjects performed sequential finger movements at 2 Hz, while for global stimulation, subjects breathed a 5% CO(2) gas mixture. Under all conditions, voxels containing primarily large veins and those containing primarily active tissue (i.e., capillaries and small veins) showed distinguishable behavior after hypercapnic normalization. This allowed functional activity to be more accurately localized and quantified based on changes in venous blood oxygenation alone. The normalized BOLD signal induced by the motor task was consistent across different magnetic fields and pulse sequences, and corresponded well with cerebral blood flow measurements. Our data suggest that the hypercapnic normalization approach can improve the spatial specificity and interpretation of BOLD signals, allowing comparison of BOLD signals across subjects, field strengths, and pulse sequences. A theoretical framework for this method is provided.

该副本是利用众多研究子项目之一 由NIH/NCRR资助的中心赠款提供的资源。子弹和 调查员（PI）可能已经从其他NIH来源获得了主要资金， 因此可以在其他清晰的条目中代表。列出的机构是 对于中心，这不一定是调查员的机构。 血液氧合水平依赖性（粗体）功能磁共振成像（fMRI）对神经刺激的信号反应受到与刺激无关的许多因素的影响。这些因素是生理的，例如静静脉静脉脑血体积（CBV（V））和血管大小以及实验性，例如脉冲序列和静态磁场强度（B（0））。因此，很难比较跨受试者，野外强度和脉冲序列的任务诱导的fMRI信号。可以通过通过全局高碳酸盐诱导的BOLD信号来标准化神经活动引起的BOLD FMRI响应来克服此问题。为了证明大胆归一化方法的有效性，在人类受试者中进行了4 t的1.5、4和7 t和7 t和Spin-Echo Bold fMRI的梯度 - 回声fMRI。为了进行神经刺激，受试者在2 Hz时进行了顺序运动，而对于全球刺激，受试者呼吸了5％CO（2）气体混合物。在所有条件下，主要含有大静脉的体素和主要是活性组织（即毛细血管和小静脉）的体素显示出高含量正常化后的可区分行为。这允许仅基于静脉血液氧合的变化而更准确地定位和量化功能活性。在不同的磁场和脉冲序列之间，由电动机任务引起的归一化粗体信号是一致的，并且与脑血流测量结果很好。我们的数据表明，高含量归一化方法可以改善大胆信号的空间特异性和解释，从而可以比较跨受试者，野外强度和脉冲序列的大胆信号。提供了此方法的理论框架。